| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Pablo Neira Ayuso | 4213 | 45.34% | 2 | 3.51% |
| Wojciech Drewek | 3058 | 32.91% | 3 | 5.26% |
| Andreas Schultz | 691 | 7.44% | 10 | 17.54% |
| Jonas Bonn | 613 | 6.60% | 8 | 14.04% |
| Taehee Yoo | 262 | 2.82% | 8 | 14.04% |
| Nicolas Dichtel | 251 | 2.70% | 3 | 5.26% |
| Johannes Berg | 66 | 0.71% | 5 | 8.77% |
| Pravin B Shelar | 55 | 0.59% | 1 | 1.75% |
| Eric Dumazet | 25 | 0.27% | 1 | 1.75% |
| Masahiro Fujiwara | 19 | 0.20% | 1 | 1.75% |
| Jakub Kiciński | 10 | 0.11% | 2 | 3.51% |
| Kees Cook | 6 | 0.06% | 1 | 1.75% |
| Yoshiyuki Kurauchi | 6 | 0.06% | 1 | 1.75% |
| Guillaume Nault | 5 | 0.05% | 1 | 1.75% |
| David S. Miller | 2 | 0.02% | 1 | 1.75% |
| Thomas Gleixner | 2 | 0.02% | 1 | 1.75% |
| Gustavo A. R. Silva | 2 | 0.02% | 1 | 1.75% |
| Gyeongun Kang | 1 | 0.01% | 1 | 1.75% |
| Zheng Yongjun | 1 | 0.01% | 1 | 1.75% |
| Sebastian Andrzej Siewior | 1 | 0.01% | 1 | 1.75% |
| Lionel Gauthier | 1 | 0.01% | 1 | 1.75% |
| Heiner Kallweit | 1 | 0.01% | 1 | 1.75% |
| Alexey Dobriyan | 1 | 0.01% | 1 | 1.75% |
| Stephen Hemminger | 1 | 0.01% | 1 | 1.75% |
| Total | 9293 | 57 |
// SPDX-License-Identifier: GPL-2.0-or-later /* GTP according to GSM TS 09.60 / 3GPP TS 29.060 * * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org> * * Author: Harald Welte <hwelte@sysmocom.de> * Pablo Neira Ayuso <pablo@netfilter.org> * Andreas Schultz <aschultz@travelping.com> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/skbuff.h> #include <linux/udp.h> #include <linux/rculist.h> #include <linux/jhash.h> #include <linux/if_tunnel.h> #include <linux/net.h> #include <linux/file.h> #include <linux/gtp.h> #include <net/net_namespace.h> #include <net/protocol.h> #include <net/ip.h> #include <net/udp.h> #include <net/udp_tunnel.h> #include <net/icmp.h> #include <net/xfrm.h> #include <net/genetlink.h> #include <net/netns/generic.h> #include <net/gtp.h> /* An active session for the subscriber. */ struct pdp_ctx { struct hlist_node hlist_tid; struct hlist_node hlist_addr; union { struct { u64 tid; u16 flow; } v0; struct { u32 i_tei; u32 o_tei; } v1; } u; u8 gtp_version; u16 af; struct in_addr ms_addr_ip4; struct in_addr peer_addr_ip4; struct sock *sk; struct net_device *dev; atomic_t tx_seq; struct rcu_head rcu_head; }; /* One instance of the GTP device. */ struct gtp_dev { struct list_head list; struct sock *sk0; struct sock *sk1u; u8 sk_created; struct net_device *dev; struct net *net; unsigned int role; unsigned int hash_size; struct hlist_head *tid_hash; struct hlist_head *addr_hash; u8 restart_count; }; struct echo_info { struct in_addr ms_addr_ip4; struct in_addr peer_addr_ip4; u8 gtp_version; }; static unsigned int gtp_net_id __read_mostly; struct gtp_net { struct list_head gtp_dev_list; }; static u32 gtp_h_initval; static struct genl_family gtp_genl_family; enum gtp_multicast_groups { GTP_GENL_MCGRP, }; static const struct genl_multicast_group gtp_genl_mcgrps[] = { [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME }, }; static void pdp_context_delete(struct pdp_ctx *pctx); static inline u32 gtp0_hashfn(u64 tid) { u32 *tid32 = (u32 *) &tid; return jhash_2words(tid32[0], tid32[1], gtp_h_initval); } static inline u32 gtp1u_hashfn(u32 tid) { return jhash_1word(tid, gtp_h_initval); } static inline u32 ipv4_hashfn(__be32 ip) { return jhash_1word((__force u32)ip, gtp_h_initval); } /* Resolve a PDP context structure based on the 64bit TID. */ static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid) { struct hlist_head *head; struct pdp_ctx *pdp; head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size]; hlist_for_each_entry_rcu(pdp, head, hlist_tid) { if (pdp->gtp_version == GTP_V0 && pdp->u.v0.tid == tid) return pdp; } return NULL; } /* Resolve a PDP context structure based on the 32bit TEI. */ static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid) { struct hlist_head *head; struct pdp_ctx *pdp; head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size]; hlist_for_each_entry_rcu(pdp, head, hlist_tid) { if (pdp->gtp_version == GTP_V1 && pdp->u.v1.i_tei == tid) return pdp; } return NULL; } /* Resolve a PDP context based on IPv4 address of MS. */ static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr) { struct hlist_head *head; struct pdp_ctx *pdp; head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size]; hlist_for_each_entry_rcu(pdp, head, hlist_addr) { if (pdp->af == AF_INET && pdp->ms_addr_ip4.s_addr == ms_addr) return pdp; } return NULL; } static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx, unsigned int hdrlen, unsigned int role) { struct iphdr *iph; if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr))) return false; iph = (struct iphdr *)(skb->data + hdrlen); if (role == GTP_ROLE_SGSN) return iph->daddr == pctx->ms_addr_ip4.s_addr; else return iph->saddr == pctx->ms_addr_ip4.s_addr; } /* Check if the inner IP address in this packet is assigned to any * existing mobile subscriber. */ static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx, unsigned int hdrlen, unsigned int role) { switch (ntohs(skb->protocol)) { case ETH_P_IP: return gtp_check_ms_ipv4(skb, pctx, hdrlen, role); } return false; } static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb, unsigned int hdrlen, unsigned int role) { if (!gtp_check_ms(skb, pctx, hdrlen, role)) { netdev_dbg(pctx->dev, "No PDP ctx for this MS\n"); return 1; } /* Get rid of the GTP + UDP headers. */ if (iptunnel_pull_header(skb, hdrlen, skb->protocol, !net_eq(sock_net(pctx->sk), dev_net(pctx->dev)))) { pctx->dev->stats.rx_length_errors++; goto err; } netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n"); /* Now that the UDP and the GTP header have been removed, set up the * new network header. This is required by the upper layer to * calculate the transport header. */ skb_reset_network_header(skb); skb_reset_mac_header(skb); skb->dev = pctx->dev; dev_sw_netstats_rx_add(pctx->dev, skb->len); __netif_rx(skb); return 0; err: pctx->dev->stats.rx_dropped++; return -1; } static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4, const struct sock *sk, __be32 daddr, __be32 saddr) { memset(fl4, 0, sizeof(*fl4)); fl4->flowi4_oif = sk->sk_bound_dev_if; fl4->daddr = daddr; fl4->saddr = saddr; fl4->flowi4_tos = RT_CONN_FLAGS(sk); fl4->flowi4_proto = sk->sk_protocol; return ip_route_output_key(sock_net(sk), fl4); } /* GSM TS 09.60. 7.3 * In all Path Management messages: * - TID: is not used and shall be set to 0. * - Flow Label is not used and shall be set to 0 * In signalling messages: * - number: this field is not yet used in signalling messages. * It shall be set to 255 by the sender and shall be ignored * by the receiver * Returns true if the echo req was correct, false otherwise. */ static bool gtp0_validate_echo_hdr(struct gtp0_header *gtp0) { return !(gtp0->tid || (gtp0->flags ^ 0x1e) || gtp0->number != 0xff || gtp0->flow); } /* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */ static void gtp0_build_echo_msg(struct gtp0_header *hdr, __u8 msg_type) { int len_pkt, len_hdr; hdr->flags = 0x1e; /* v0, GTP-non-prime. */ hdr->type = msg_type; /* GSM TS 09.60. 7.3 In all Path Management Flow Label and TID * are not used and shall be set to 0. */ hdr->flow = 0; hdr->tid = 0; hdr->number = 0xff; hdr->spare[0] = 0xff; hdr->spare[1] = 0xff; hdr->spare[2] = 0xff; len_pkt = sizeof(struct gtp0_packet); len_hdr = sizeof(struct gtp0_header); if (msg_type == GTP_ECHO_RSP) hdr->length = htons(len_pkt - len_hdr); else hdr->length = 0; } static int gtp0_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) { struct gtp0_packet *gtp_pkt; struct gtp0_header *gtp0; struct rtable *rt; struct flowi4 fl4; struct iphdr *iph; __be16 seq; gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); if (!gtp0_validate_echo_hdr(gtp0)) return -1; seq = gtp0->seq; /* pull GTP and UDP headers */ skb_pull_data(skb, sizeof(struct gtp0_header) + sizeof(struct udphdr)); gtp_pkt = skb_push(skb, sizeof(struct gtp0_packet)); memset(gtp_pkt, 0, sizeof(struct gtp0_packet)); gtp0_build_echo_msg(>p_pkt->gtp0_h, GTP_ECHO_RSP); /* GSM TS 09.60. 7.3 The Sequence Number in a signalling response * message shall be copied from the signalling request message * that the GSN is replying to. */ gtp_pkt->gtp0_h.seq = seq; gtp_pkt->ie.tag = GTPIE_RECOVERY; gtp_pkt->ie.val = gtp->restart_count; iph = ip_hdr(skb); /* find route to the sender, * src address becomes dst address and vice versa. */ rt = ip4_route_output_gtp(&fl4, gtp->sk0, iph->saddr, iph->daddr); if (IS_ERR(rt)) { netdev_dbg(gtp->dev, "no route for echo response from %pI4\n", &iph->saddr); return -1; } udp_tunnel_xmit_skb(rt, gtp->sk0, skb, fl4.saddr, fl4.daddr, iph->tos, ip4_dst_hoplimit(&rt->dst), 0, htons(GTP0_PORT), htons(GTP0_PORT), !net_eq(sock_net(gtp->sk1u), dev_net(gtp->dev)), false); return 0; } static int gtp_genl_fill_echo(struct sk_buff *skb, u32 snd_portid, u32 snd_seq, int flags, u32 type, struct echo_info echo) { void *genlh; genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags, type); if (!genlh) goto failure; if (nla_put_u32(skb, GTPA_VERSION, echo.gtp_version) || nla_put_be32(skb, GTPA_PEER_ADDRESS, echo.peer_addr_ip4.s_addr) || nla_put_be32(skb, GTPA_MS_ADDRESS, echo.ms_addr_ip4.s_addr)) goto failure; genlmsg_end(skb, genlh); return 0; failure: genlmsg_cancel(skb, genlh); return -EMSGSIZE; } static int gtp0_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) { struct gtp0_header *gtp0; struct echo_info echo; struct sk_buff *msg; struct iphdr *iph; int ret; gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); if (!gtp0_validate_echo_hdr(gtp0)) return -1; iph = ip_hdr(skb); echo.ms_addr_ip4.s_addr = iph->daddr; echo.peer_addr_ip4.s_addr = iph->saddr; echo.gtp_version = GTP_V0; msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); if (!msg) return -ENOMEM; ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo); if (ret < 0) { nlmsg_free(msg); return ret; } return genlmsg_multicast_netns(>p_genl_family, dev_net(gtp->dev), msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC); } /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */ static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) { unsigned int hdrlen = sizeof(struct udphdr) + sizeof(struct gtp0_header); struct gtp0_header *gtp0; struct pdp_ctx *pctx; if (!pskb_may_pull(skb, hdrlen)) return -1; gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); if ((gtp0->flags >> 5) != GTP_V0) return 1; /* If the sockets were created in kernel, it means that * there is no daemon running in userspace which would * handle echo request. */ if (gtp0->type == GTP_ECHO_REQ && gtp->sk_created) return gtp0_send_echo_resp(gtp, skb); if (gtp0->type == GTP_ECHO_RSP && gtp->sk_created) return gtp0_handle_echo_resp(gtp, skb); if (gtp0->type != GTP_TPDU) return 1; pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid)); if (!pctx) { netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb); return 1; } return gtp_rx(pctx, skb, hdrlen, gtp->role); } /* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */ static void gtp1u_build_echo_msg(struct gtp1_header_long *hdr, __u8 msg_type) { int len_pkt, len_hdr; /* S flag must be set to 1 */ hdr->flags = 0x32; /* v1, GTP-non-prime. */ hdr->type = msg_type; /* 3GPP TS 29.281 5.1 - TEID has to be set to 0 */ hdr->tid = 0; /* seq, npdu and next should be counted to the length of the GTP packet * that's why szie of gtp1_header should be subtracted, * not size of gtp1_header_long. */ len_hdr = sizeof(struct gtp1_header); if (msg_type == GTP_ECHO_RSP) { len_pkt = sizeof(struct gtp1u_packet); hdr->length = htons(len_pkt - len_hdr); } else { /* GTP_ECHO_REQ does not carry GTP Information Element, * the why gtp1_header_long is used here. */ len_pkt = sizeof(struct gtp1_header_long); hdr->length = htons(len_pkt - len_hdr); } } static int gtp1u_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) { struct gtp1_header_long *gtp1u; struct gtp1u_packet *gtp_pkt; struct rtable *rt; struct flowi4 fl4; struct iphdr *iph; gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr)); /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response, * Error Indication and Supported Extension Headers Notification * messages, the S flag shall be set to 1 and TEID shall be set to 0. */ if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid) return -1; /* pull GTP and UDP headers */ skb_pull_data(skb, sizeof(struct gtp1_header_long) + sizeof(struct udphdr)); gtp_pkt = skb_push(skb, sizeof(struct gtp1u_packet)); memset(gtp_pkt, 0, sizeof(struct gtp1u_packet)); gtp1u_build_echo_msg(>p_pkt->gtp1u_h, GTP_ECHO_RSP); /* 3GPP TS 29.281 7.7.2 - The Restart Counter value in the * Recovery information element shall not be used, i.e. it shall * be set to zero by the sender and shall be ignored by the receiver. * The Recovery information element is mandatory due to backwards * compatibility reasons. */ gtp_pkt->ie.tag = GTPIE_RECOVERY; gtp_pkt->ie.val = 0; iph = ip_hdr(skb); /* find route to the sender, * src address becomes dst address and vice versa. */ rt = ip4_route_output_gtp(&fl4, gtp->sk1u, iph->saddr, iph->daddr); if (IS_ERR(rt)) { netdev_dbg(gtp->dev, "no route for echo response from %pI4\n", &iph->saddr); return -1; } udp_tunnel_xmit_skb(rt, gtp->sk1u, skb, fl4.saddr, fl4.daddr, iph->tos, ip4_dst_hoplimit(&rt->dst), 0, htons(GTP1U_PORT), htons(GTP1U_PORT), !net_eq(sock_net(gtp->sk1u), dev_net(gtp->dev)), false); return 0; } static int gtp1u_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) { struct gtp1_header_long *gtp1u; struct echo_info echo; struct sk_buff *msg; struct iphdr *iph; int ret; gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr)); /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response, * Error Indication and Supported Extension Headers Notification * messages, the S flag shall be set to 1 and TEID shall be set to 0. */ if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid) return -1; iph = ip_hdr(skb); echo.ms_addr_ip4.s_addr = iph->daddr; echo.peer_addr_ip4.s_addr = iph->saddr; echo.gtp_version = GTP_V1; msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); if (!msg) return -ENOMEM; ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo); if (ret < 0) { nlmsg_free(msg); return ret; } return genlmsg_multicast_netns(>p_genl_family, dev_net(gtp->dev), msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC); } static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) { unsigned int hdrlen = sizeof(struct udphdr) + sizeof(struct gtp1_header); struct gtp1_header *gtp1; struct pdp_ctx *pctx; if (!pskb_may_pull(skb, hdrlen)) return -1; gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); if ((gtp1->flags >> 5) != GTP_V1) return 1; /* If the sockets were created in kernel, it means that * there is no daemon running in userspace which would * handle echo request. */ if (gtp1->type == GTP_ECHO_REQ && gtp->sk_created) return gtp1u_send_echo_resp(gtp, skb); if (gtp1->type == GTP_ECHO_RSP && gtp->sk_created) return gtp1u_handle_echo_resp(gtp, skb); if (gtp1->type != GTP_TPDU) return 1; /* From 29.060: "This field shall be present if and only if any one or * more of the S, PN and E flags are set.". * * If any of the bit is set, then the remaining ones also have to be * set. */ if (gtp1->flags & GTP1_F_MASK) hdrlen += 4; /* Make sure the header is larger enough, including extensions. */ if (!pskb_may_pull(skb, hdrlen)) return -1; gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid)); if (!pctx) { netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb); return 1; } return gtp_rx(pctx, skb, hdrlen, gtp->role); } static void __gtp_encap_destroy(struct sock *sk) { struct gtp_dev *gtp; lock_sock(sk); gtp = sk->sk_user_data; if (gtp) { if (gtp->sk0 == sk) gtp->sk0 = NULL; else gtp->sk1u = NULL; udp_sk(sk)->encap_type = 0; rcu_assign_sk_user_data(sk, NULL); sock_put(sk); } release_sock(sk); } static void gtp_encap_destroy(struct sock *sk) { rtnl_lock(); __gtp_encap_destroy(sk); rtnl_unlock(); } static void gtp_encap_disable_sock(struct sock *sk) { if (!sk) return; __gtp_encap_destroy(sk); } static void gtp_encap_disable(struct gtp_dev *gtp) { if (gtp->sk_created) { udp_tunnel_sock_release(gtp->sk0->sk_socket); udp_tunnel_sock_release(gtp->sk1u->sk_socket); gtp->sk_created = false; gtp->sk0 = NULL; gtp->sk1u = NULL; } else { gtp_encap_disable_sock(gtp->sk0); gtp_encap_disable_sock(gtp->sk1u); } } /* UDP encapsulation receive handler. See net/ipv4/udp.c. * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket. */ static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb) { struct gtp_dev *gtp; int ret = 0; gtp = rcu_dereference_sk_user_data(sk); if (!gtp) return 1; netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk); switch (udp_sk(sk)->encap_type) { case UDP_ENCAP_GTP0: netdev_dbg(gtp->dev, "received GTP0 packet\n"); ret = gtp0_udp_encap_recv(gtp, skb); break; case UDP_ENCAP_GTP1U: netdev_dbg(gtp->dev, "received GTP1U packet\n"); ret = gtp1u_udp_encap_recv(gtp, skb); break; default: ret = -1; /* Shouldn't happen. */ } switch (ret) { case 1: netdev_dbg(gtp->dev, "pass up to the process\n"); break; case 0: break; case -1: netdev_dbg(gtp->dev, "GTP packet has been dropped\n"); kfree_skb(skb); ret = 0; break; } return ret; } static int gtp_dev_init(struct net_device *dev) { struct gtp_dev *gtp = netdev_priv(dev); gtp->dev = dev; dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); if (!dev->tstats) return -ENOMEM; return 0; } static void gtp_dev_uninit(struct net_device *dev) { struct gtp_dev *gtp = netdev_priv(dev); gtp_encap_disable(gtp); free_percpu(dev->tstats); } static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) { int payload_len = skb->len; struct gtp0_header *gtp0; gtp0 = skb_push(skb, sizeof(*gtp0)); gtp0->flags = 0x1e; /* v0, GTP-non-prime. */ gtp0->type = GTP_TPDU; gtp0->length = htons(payload_len); gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff); gtp0->flow = htons(pctx->u.v0.flow); gtp0->number = 0xff; gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff; gtp0->tid = cpu_to_be64(pctx->u.v0.tid); } static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) { int payload_len = skb->len; struct gtp1_header *gtp1; gtp1 = skb_push(skb, sizeof(*gtp1)); /* Bits 8 7 6 5 4 3 2 1 * +--+--+--+--+--+--+--+--+ * |version |PT| 0| E| S|PN| * +--+--+--+--+--+--+--+--+ * 0 0 1 1 1 0 0 0 */ gtp1->flags = 0x30; /* v1, GTP-non-prime. */ gtp1->type = GTP_TPDU; gtp1->length = htons(payload_len); gtp1->tid = htonl(pctx->u.v1.o_tei); /* TODO: Support for extension header, sequence number and N-PDU. * Update the length field if any of them is available. */ } struct gtp_pktinfo { struct sock *sk; struct iphdr *iph; struct flowi4 fl4; struct rtable *rt; struct pdp_ctx *pctx; struct net_device *dev; __be16 gtph_port; }; static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo) { switch (pktinfo->pctx->gtp_version) { case GTP_V0: pktinfo->gtph_port = htons(GTP0_PORT); gtp0_push_header(skb, pktinfo->pctx); break; case GTP_V1: pktinfo->gtph_port = htons(GTP1U_PORT); gtp1_push_header(skb, pktinfo->pctx); break; } } static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo, struct sock *sk, struct iphdr *iph, struct pdp_ctx *pctx, struct rtable *rt, struct flowi4 *fl4, struct net_device *dev) { pktinfo->sk = sk; pktinfo->iph = iph; pktinfo->pctx = pctx; pktinfo->rt = rt; pktinfo->fl4 = *fl4; pktinfo->dev = dev; } static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev, struct gtp_pktinfo *pktinfo) { struct gtp_dev *gtp = netdev_priv(dev); struct pdp_ctx *pctx; struct rtable *rt; struct flowi4 fl4; struct iphdr *iph; __be16 df; int mtu; /* Read the IP destination address and resolve the PDP context. * Prepend PDP header with TEI/TID from PDP ctx. */ iph = ip_hdr(skb); if (gtp->role == GTP_ROLE_SGSN) pctx = ipv4_pdp_find(gtp, iph->saddr); else pctx = ipv4_pdp_find(gtp, iph->daddr); if (!pctx) { netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n", &iph->daddr); return -ENOENT; } netdev_dbg(dev, "found PDP context %p\n", pctx); rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr, inet_sk(pctx->sk)->inet_saddr); if (IS_ERR(rt)) { netdev_dbg(dev, "no route to SSGN %pI4\n", &pctx->peer_addr_ip4.s_addr); dev->stats.tx_carrier_errors++; goto err; } if (rt->dst.dev == dev) { netdev_dbg(dev, "circular route to SSGN %pI4\n", &pctx->peer_addr_ip4.s_addr); dev->stats.collisions++; goto err_rt; } /* This is similar to tnl_update_pmtu(). */ df = iph->frag_off; if (df) { mtu = dst_mtu(&rt->dst) - dev->hard_header_len - sizeof(struct iphdr) - sizeof(struct udphdr); switch (pctx->gtp_version) { case GTP_V0: mtu -= sizeof(struct gtp0_header); break; case GTP_V1: mtu -= sizeof(struct gtp1_header); break; } } else { mtu = dst_mtu(&rt->dst); } skb_dst_update_pmtu_no_confirm(skb, mtu); if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) && mtu < ntohs(iph->tot_len)) { netdev_dbg(dev, "packet too big, fragmentation needed\n"); icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); goto err_rt; } gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev); gtp_push_header(skb, pktinfo); return 0; err_rt: ip_rt_put(rt); err: return -EBADMSG; } static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev) { unsigned int proto = ntohs(skb->protocol); struct gtp_pktinfo pktinfo; int err; /* Ensure there is sufficient headroom. */ if (skb_cow_head(skb, dev->needed_headroom)) goto tx_err; skb_reset_inner_headers(skb); /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */ rcu_read_lock(); switch (proto) { case ETH_P_IP: err = gtp_build_skb_ip4(skb, dev, &pktinfo); break; default: err = -EOPNOTSUPP; break; } rcu_read_unlock(); if (err < 0) goto tx_err; switch (proto) { case ETH_P_IP: netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n", &pktinfo.iph->saddr, &pktinfo.iph->daddr); udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb, pktinfo.fl4.saddr, pktinfo.fl4.daddr, pktinfo.iph->tos, ip4_dst_hoplimit(&pktinfo.rt->dst), 0, pktinfo.gtph_port, pktinfo.gtph_port, !net_eq(sock_net(pktinfo.pctx->sk), dev_net(dev)), false); break; } return NETDEV_TX_OK; tx_err: dev->stats.tx_errors++; dev_kfree_skb(skb); return NETDEV_TX_OK; } static const struct net_device_ops gtp_netdev_ops = { .ndo_init = gtp_dev_init, .ndo_uninit = gtp_dev_uninit, .ndo_start_xmit = gtp_dev_xmit, .ndo_get_stats64 = dev_get_tstats64, }; static const struct device_type gtp_type = { .name = "gtp", }; static void gtp_link_setup(struct net_device *dev) { unsigned int max_gtp_header_len = sizeof(struct iphdr) + sizeof(struct udphdr) + sizeof(struct gtp0_header); dev->netdev_ops = >p_netdev_ops; dev->needs_free_netdev = true; SET_NETDEV_DEVTYPE(dev, >p_type); dev->hard_header_len = 0; dev->addr_len = 0; dev->mtu = ETH_DATA_LEN - max_gtp_header_len; /* Zero header length. */ dev->type = ARPHRD_NONE; dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; dev->priv_flags |= IFF_NO_QUEUE; dev->features |= NETIF_F_LLTX; netif_keep_dst(dev); dev->needed_headroom = LL_MAX_HEADER + max_gtp_header_len; } static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize); static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]); static void gtp_destructor(struct net_device *dev) { struct gtp_dev *gtp = netdev_priv(dev); kfree(gtp->addr_hash); kfree(gtp->tid_hash); } static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp) { struct udp_tunnel_sock_cfg tuncfg = {}; struct udp_port_cfg udp_conf = { .local_ip.s_addr = htonl(INADDR_ANY), .family = AF_INET, }; struct net *net = gtp->net; struct socket *sock; int err; if (type == UDP_ENCAP_GTP0) udp_conf.local_udp_port = htons(GTP0_PORT); else if (type == UDP_ENCAP_GTP1U) udp_conf.local_udp_port = htons(GTP1U_PORT); else return ERR_PTR(-EINVAL); err = udp_sock_create(net, &udp_conf, &sock); if (err) return ERR_PTR(err); tuncfg.sk_user_data = gtp; tuncfg.encap_type = type; tuncfg.encap_rcv = gtp_encap_recv; tuncfg.encap_destroy = NULL; setup_udp_tunnel_sock(net, sock, &tuncfg); return sock->sk; } static int gtp_create_sockets(struct gtp_dev *gtp, struct nlattr *data[]) { struct sock *sk1u = NULL; struct sock *sk0 = NULL; sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp); if (IS_ERR(sk0)) return PTR_ERR(sk0); sk1u = gtp_create_sock(UDP_ENCAP_GTP1U, gtp); if (IS_ERR(sk1u)) { udp_tunnel_sock_release(sk0->sk_socket); return PTR_ERR(sk1u); } gtp->sk_created = true; gtp->sk0 = sk0; gtp->sk1u = sk1u; return 0; } static int gtp_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { unsigned int role = GTP_ROLE_GGSN; struct gtp_dev *gtp; struct gtp_net *gn; int hashsize, err; gtp = netdev_priv(dev); if (!data[IFLA_GTP_PDP_HASHSIZE]) { hashsize = 1024; } else { hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]); if (!hashsize) hashsize = 1024; } if (data[IFLA_GTP_ROLE]) { role = nla_get_u32(data[IFLA_GTP_ROLE]); if (role > GTP_ROLE_SGSN) return -EINVAL; } gtp->role = role; if (!data[IFLA_GTP_RESTART_COUNT]) gtp->restart_count = 0; else gtp->restart_count = nla_get_u8(data[IFLA_GTP_RESTART_COUNT]); gtp->net = src_net; err = gtp_hashtable_new(gtp, hashsize); if (err < 0) return err; if (data[IFLA_GTP_CREATE_SOCKETS]) err = gtp_create_sockets(gtp, data); else err = gtp_encap_enable(gtp, data); if (err < 0) goto out_hashtable; err = register_netdevice(dev); if (err < 0) { netdev_dbg(dev, "failed to register new netdev %d\n", err); goto out_encap; } gn = net_generic(dev_net(dev), gtp_net_id); list_add_rcu(>p->list, &gn->gtp_dev_list); dev->priv_destructor = gtp_destructor; netdev_dbg(dev, "registered new GTP interface\n"); return 0; out_encap: gtp_encap_disable(gtp); out_hashtable: kfree(gtp->addr_hash); kfree(gtp->tid_hash); return err; } static void gtp_dellink(struct net_device *dev, struct list_head *head) { struct gtp_dev *gtp = netdev_priv(dev); struct pdp_ctx *pctx; int i; for (i = 0; i < gtp->hash_size; i++) hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) pdp_context_delete(pctx); list_del_rcu(>p->list); unregister_netdevice_queue(dev, head); } static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = { [IFLA_GTP_FD0] = { .type = NLA_U32 }, [IFLA_GTP_FD1] = { .type = NLA_U32 }, [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 }, [IFLA_GTP_ROLE] = { .type = NLA_U32 }, [IFLA_GTP_CREATE_SOCKETS] = { .type = NLA_U8 }, [IFLA_GTP_RESTART_COUNT] = { .type = NLA_U8 }, }; static int gtp_validate(struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { if (!data) return -EINVAL; return 0; } static size_t gtp_get_size(const struct net_device *dev) { return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */ nla_total_size(sizeof(__u32)) + /* IFLA_GTP_ROLE */ nla_total_size(sizeof(__u8)); /* IFLA_GTP_RESTART_COUNT */ } static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev) { struct gtp_dev *gtp = netdev_priv(dev); if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size)) goto nla_put_failure; if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role)) goto nla_put_failure; if (nla_put_u8(skb, IFLA_GTP_RESTART_COUNT, gtp->restart_count)) goto nla_put_failure; return 0; nla_put_failure: return -EMSGSIZE; } static struct rtnl_link_ops gtp_link_ops __read_mostly = { .kind = "gtp", .maxtype = IFLA_GTP_MAX, .policy = gtp_policy, .priv_size = sizeof(struct gtp_dev), .setup = gtp_link_setup, .validate = gtp_validate, .newlink = gtp_newlink, .dellink = gtp_dellink, .get_size = gtp_get_size, .fill_info = gtp_fill_info, }; static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize) { int i; gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head), GFP_KERNEL | __GFP_NOWARN); if (gtp->addr_hash == NULL) return -ENOMEM; gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head), GFP_KERNEL | __GFP_NOWARN); if (gtp->tid_hash == NULL) goto err1; gtp->hash_size = hsize; for (i = 0; i < hsize; i++) { INIT_HLIST_HEAD(>p->addr_hash[i]); INIT_HLIST_HEAD(>p->tid_hash[i]); } return 0; err1: kfree(gtp->addr_hash); return -ENOMEM; } static struct sock *gtp_encap_enable_socket(int fd, int type, struct gtp_dev *gtp) { struct udp_tunnel_sock_cfg tuncfg = {NULL}; struct socket *sock; struct sock *sk; int err; pr_debug("enable gtp on %d, %d\n", fd, type); sock = sockfd_lookup(fd, &err); if (!sock) { pr_debug("gtp socket fd=%d not found\n", fd); return NULL; } sk = sock->sk; if (sk->sk_protocol != IPPROTO_UDP || sk->sk_type != SOCK_DGRAM || (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) { pr_debug("socket fd=%d not UDP\n", fd); sk = ERR_PTR(-EINVAL); goto out_sock; } lock_sock(sk); if (sk->sk_user_data) { sk = ERR_PTR(-EBUSY); goto out_rel_sock; } sock_hold(sk); tuncfg.sk_user_data = gtp; tuncfg.encap_type = type; tuncfg.encap_rcv = gtp_encap_recv; tuncfg.encap_destroy = gtp_encap_destroy; setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg); out_rel_sock: release_sock(sock->sk); out_sock: sockfd_put(sock); return sk; } static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]) { struct sock *sk1u = NULL; struct sock *sk0 = NULL; if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1]) return -EINVAL; if (data[IFLA_GTP_FD0]) { u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]); sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp); if (IS_ERR(sk0)) return PTR_ERR(sk0); } if (data[IFLA_GTP_FD1]) { u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]); sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp); if (IS_ERR(sk1u)) { gtp_encap_disable_sock(sk0); return PTR_ERR(sk1u); } } gtp->sk0 = sk0; gtp->sk1u = sk1u; return 0; } static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[]) { struct gtp_dev *gtp = NULL; struct net_device *dev; struct net *net; /* Examine the link attributes and figure out which network namespace * we are talking about. */ if (nla[GTPA_NET_NS_FD]) net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD])); else net = get_net(src_net); if (IS_ERR(net)) return NULL; /* Check if there's an existing gtpX device to configure */ dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK])); if (dev && dev->netdev_ops == >p_netdev_ops) gtp = netdev_priv(dev); put_net(net); return gtp; } static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info) { pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]); pctx->af = AF_INET; pctx->peer_addr_ip4.s_addr = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]); pctx->ms_addr_ip4.s_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); switch (pctx->gtp_version) { case GTP_V0: /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow * label needs to be the same for uplink and downlink packets, * so let's annotate this. */ pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]); pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]); break; case GTP_V1: pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]); pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]); break; default: break; } } static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk, struct genl_info *info) { struct pdp_ctx *pctx, *pctx_tid = NULL; struct net_device *dev = gtp->dev; u32 hash_ms, hash_tid = 0; unsigned int version; bool found = false; __be32 ms_addr; ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size; version = nla_get_u32(info->attrs[GTPA_VERSION]); pctx = ipv4_pdp_find(gtp, ms_addr); if (pctx) found = true; if (version == GTP_V0) pctx_tid = gtp0_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_TID])); else if (version == GTP_V1) pctx_tid = gtp1_pdp_find(gtp, nla_get_u32(info->attrs[GTPA_I_TEI])); if (pctx_tid) found = true; if (found) { if (info->nlhdr->nlmsg_flags & NLM_F_EXCL) return ERR_PTR(-EEXIST); if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE) return ERR_PTR(-EOPNOTSUPP); if (pctx && pctx_tid) return ERR_PTR(-EEXIST); if (!pctx) pctx = pctx_tid; ipv4_pdp_fill(pctx, info); if (pctx->gtp_version == GTP_V0) netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n", pctx->u.v0.tid, pctx); else if (pctx->gtp_version == GTP_V1) netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n", pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); return pctx; } pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC); if (pctx == NULL) return ERR_PTR(-ENOMEM); sock_hold(sk); pctx->sk = sk; pctx->dev = gtp->dev; ipv4_pdp_fill(pctx, info); atomic_set(&pctx->tx_seq, 0); switch (pctx->gtp_version) { case GTP_V0: /* TS 09.60: "The flow label identifies unambiguously a GTP * flow.". We use the tid for this instead, I cannot find a * situation in which this doesn't unambiguosly identify the * PDP context. */ hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size; break; case GTP_V1: hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size; break; } hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]); hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]); switch (pctx->gtp_version) { case GTP_V0: netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n", pctx->u.v0.tid, &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx); break; case GTP_V1: netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n", pctx->u.v1.i_tei, pctx->u.v1.o_tei, &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx); break; } return pctx; } static void pdp_context_free(struct rcu_head *head) { struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head); sock_put(pctx->sk); kfree(pctx); } static void pdp_context_delete(struct pdp_ctx *pctx) { hlist_del_rcu(&pctx->hlist_tid); hlist_del_rcu(&pctx->hlist_addr); call_rcu(&pctx->rcu_head, pdp_context_free); } static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation); static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) { unsigned int version; struct pdp_ctx *pctx; struct gtp_dev *gtp; struct sock *sk; int err; if (!info->attrs[GTPA_VERSION] || !info->attrs[GTPA_LINK] || !info->attrs[GTPA_PEER_ADDRESS] || !info->attrs[GTPA_MS_ADDRESS]) return -EINVAL; version = nla_get_u32(info->attrs[GTPA_VERSION]); switch (version) { case GTP_V0: if (!info->attrs[GTPA_TID] || !info->attrs[GTPA_FLOW]) return -EINVAL; break; case GTP_V1: if (!info->attrs[GTPA_I_TEI] || !info->attrs[GTPA_O_TEI]) return -EINVAL; break; default: return -EINVAL; } rtnl_lock(); gtp = gtp_find_dev(sock_net(skb->sk), info->attrs); if (!gtp) { err = -ENODEV; goto out_unlock; } if (version == GTP_V0) sk = gtp->sk0; else if (version == GTP_V1) sk = gtp->sk1u; else sk = NULL; if (!sk) { err = -ENODEV; goto out_unlock; } pctx = gtp_pdp_add(gtp, sk, info); if (IS_ERR(pctx)) { err = PTR_ERR(pctx); } else { gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL); err = 0; } out_unlock: rtnl_unlock(); return err; } static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net, struct nlattr *nla[]) { struct gtp_dev *gtp; gtp = gtp_find_dev(net, nla); if (!gtp) return ERR_PTR(-ENODEV); if (nla[GTPA_MS_ADDRESS]) { __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]); return ipv4_pdp_find(gtp, ip); } else if (nla[GTPA_VERSION]) { u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]); if (gtp_version == GTP_V0 && nla[GTPA_TID]) return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID])); else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI]) return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI])); } return ERR_PTR(-EINVAL); } static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[]) { struct pdp_ctx *pctx; if (nla[GTPA_LINK]) pctx = gtp_find_pdp_by_link(net, nla); else pctx = ERR_PTR(-EINVAL); if (!pctx) pctx = ERR_PTR(-ENOENT); return pctx; } static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info) { struct pdp_ctx *pctx; int err = 0; if (!info->attrs[GTPA_VERSION]) return -EINVAL; rcu_read_lock(); pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); if (IS_ERR(pctx)) { err = PTR_ERR(pctx); goto out_unlock; } if (pctx->gtp_version == GTP_V0) netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n", pctx->u.v0.tid, pctx); else if (pctx->gtp_version == GTP_V1) netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n", pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC); pdp_context_delete(pctx); out_unlock: rcu_read_unlock(); return err; } static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq, int flags, u32 type, struct pdp_ctx *pctx) { void *genlh; genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags, type); if (genlh == NULL) goto nlmsg_failure; if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) || nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) || nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) || nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr)) goto nla_put_failure; switch (pctx->gtp_version) { case GTP_V0: if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) || nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow)) goto nla_put_failure; break; case GTP_V1: if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) || nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei)) goto nla_put_failure; break; } genlmsg_end(skb, genlh); return 0; nlmsg_failure: nla_put_failure: genlmsg_cancel(skb, genlh); return -EMSGSIZE; } static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation) { struct sk_buff *msg; int ret; msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation); if (!msg) return -ENOMEM; ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx); if (ret < 0) { nlmsg_free(msg); return ret; } ret = genlmsg_multicast_netns(>p_genl_family, dev_net(pctx->dev), msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC); return ret; } static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info) { struct pdp_ctx *pctx = NULL; struct sk_buff *skb2; int err; if (!info->attrs[GTPA_VERSION]) return -EINVAL; rcu_read_lock(); pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs); if (IS_ERR(pctx)) { err = PTR_ERR(pctx); goto err_unlock; } skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); if (skb2 == NULL) { err = -ENOMEM; goto err_unlock; } err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq, 0, info->nlhdr->nlmsg_type, pctx); if (err < 0) goto err_unlock_free; rcu_read_unlock(); return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid); err_unlock_free: kfree_skb(skb2); err_unlock: rcu_read_unlock(); return err; } static int gtp_genl_dump_pdp(struct sk_buff *skb, struct netlink_callback *cb) { struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp; int i, j, bucket = cb->args[0], skip = cb->args[1]; struct net *net = sock_net(skb->sk); struct pdp_ctx *pctx; struct gtp_net *gn; gn = net_generic(net, gtp_net_id); if (cb->args[4]) return 0; rcu_read_lock(); list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) { if (last_gtp && last_gtp != gtp) continue; else last_gtp = NULL; for (i = bucket; i < gtp->hash_size; i++) { j = 0; hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) { if (j >= skip && gtp_genl_fill_info(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh->nlmsg_type, pctx)) { cb->args[0] = i; cb->args[1] = j; cb->args[2] = (unsigned long)gtp; goto out; } j++; } skip = 0; } bucket = 0; } cb->args[4] = 1; out: rcu_read_unlock(); return skb->len; } static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info) { struct sk_buff *skb_to_send; __be32 src_ip, dst_ip; unsigned int version; struct gtp_dev *gtp; struct flowi4 fl4; struct rtable *rt; struct sock *sk; __be16 port; int len; if (!info->attrs[GTPA_VERSION] || !info->attrs[GTPA_LINK] || !info->attrs[GTPA_PEER_ADDRESS] || !info->attrs[GTPA_MS_ADDRESS]) return -EINVAL; version = nla_get_u32(info->attrs[GTPA_VERSION]); dst_ip = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]); src_ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); gtp = gtp_find_dev(sock_net(skb->sk), info->attrs); if (!gtp) return -ENODEV; if (!gtp->sk_created) return -EOPNOTSUPP; if (!(gtp->dev->flags & IFF_UP)) return -ENETDOWN; if (version == GTP_V0) { struct gtp0_header *gtp0_h; len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) + sizeof(struct iphdr) + sizeof(struct udphdr); skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len); if (!skb_to_send) return -ENOMEM; sk = gtp->sk0; port = htons(GTP0_PORT); gtp0_h = skb_push(skb_to_send, sizeof(struct gtp0_header)); memset(gtp0_h, 0, sizeof(struct gtp0_header)); gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ); } else if (version == GTP_V1) { struct gtp1_header_long *gtp1u_h; len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp1_header_long) + sizeof(struct iphdr) + sizeof(struct udphdr); skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len); if (!skb_to_send) return -ENOMEM; sk = gtp->sk1u; port = htons(GTP1U_PORT); gtp1u_h = skb_push(skb_to_send, sizeof(struct gtp1_header_long)); memset(gtp1u_h, 0, sizeof(struct gtp1_header_long)); gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ); } else { return -ENODEV; } rt = ip4_route_output_gtp(&fl4, sk, dst_ip, src_ip); if (IS_ERR(rt)) { netdev_dbg(gtp->dev, "no route for echo request to %pI4\n", &dst_ip); kfree_skb(skb_to_send); return -ENODEV; } udp_tunnel_xmit_skb(rt, sk, skb_to_send, fl4.saddr, fl4.daddr, fl4.flowi4_tos, ip4_dst_hoplimit(&rt->dst), 0, port, port, !net_eq(sock_net(sk), dev_net(gtp->dev)), false); return 0; } static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = { [GTPA_LINK] = { .type = NLA_U32, }, [GTPA_VERSION] = { .type = NLA_U32, }, [GTPA_TID] = { .type = NLA_U64, }, [GTPA_PEER_ADDRESS] = { .type = NLA_U32, }, [GTPA_MS_ADDRESS] = { .type = NLA_U32, }, [GTPA_FLOW] = { .type = NLA_U16, }, [GTPA_NET_NS_FD] = { .type = NLA_U32, }, [GTPA_I_TEI] = { .type = NLA_U32, }, [GTPA_O_TEI] = { .type = NLA_U32, }, }; static const struct genl_small_ops gtp_genl_ops[] = { { .cmd = GTP_CMD_NEWPDP, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .doit = gtp_genl_new_pdp, .flags = GENL_ADMIN_PERM, }, { .cmd = GTP_CMD_DELPDP, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .doit = gtp_genl_del_pdp, .flags = GENL_ADMIN_PERM, }, { .cmd = GTP_CMD_GETPDP, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .doit = gtp_genl_get_pdp, .dumpit = gtp_genl_dump_pdp, .flags = GENL_ADMIN_PERM, }, { .cmd = GTP_CMD_ECHOREQ, .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, .doit = gtp_genl_send_echo_req, .flags = GENL_ADMIN_PERM, }, }; static struct genl_family gtp_genl_family __ro_after_init = { .name = "gtp", .version = 0, .hdrsize = 0, .maxattr = GTPA_MAX, .policy = gtp_genl_policy, .netnsok = true, .module = THIS_MODULE, .small_ops = gtp_genl_ops, .n_small_ops = ARRAY_SIZE(gtp_genl_ops), .resv_start_op = GTP_CMD_ECHOREQ + 1, .mcgrps = gtp_genl_mcgrps, .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps), }; static int __net_init gtp_net_init(struct net *net) { struct gtp_net *gn = net_generic(net, gtp_net_id); INIT_LIST_HEAD(&gn->gtp_dev_list); return 0; } static void __net_exit gtp_net_exit(struct net *net) { struct gtp_net *gn = net_generic(net, gtp_net_id); struct gtp_dev *gtp; LIST_HEAD(list); rtnl_lock(); list_for_each_entry(gtp, &gn->gtp_dev_list, list) gtp_dellink(gtp->dev, &list); unregister_netdevice_many(&list); rtnl_unlock(); } static struct pernet_operations gtp_net_ops = { .init = gtp_net_init, .exit = gtp_net_exit, .id = >p_net_id, .size = sizeof(struct gtp_net), }; static int __init gtp_init(void) { int err; get_random_bytes(>p_h_initval, sizeof(gtp_h_initval)); err = rtnl_link_register(>p_link_ops); if (err < 0) goto error_out; err = genl_register_family(>p_genl_family); if (err < 0) goto unreg_rtnl_link; err = register_pernet_subsys(>p_net_ops); if (err < 0) goto unreg_genl_family; pr_info("GTP module loaded (pdp ctx size %zd bytes)\n", sizeof(struct pdp_ctx)); return 0; unreg_genl_family: genl_unregister_family(>p_genl_family); unreg_rtnl_link: rtnl_link_unregister(>p_link_ops); error_out: pr_err("error loading GTP module loaded\n"); return err; } late_initcall(gtp_init); static void __exit gtp_fini(void) { genl_unregister_family(>p_genl_family); rtnl_link_unregister(>p_link_ops); unregister_pernet_subsys(>p_net_ops); pr_info("GTP module unloaded\n"); } module_exit(gtp_fini); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>"); MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic"); MODULE_ALIAS_RTNL_LINK("gtp"); MODULE_ALIAS_GENL_FAMILY("gtp");
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